Straight hole drilling device



Re. A20,405

June 8, 1937. v. E. sT`RoUD STRAIGHT HOLE DRILLING DEVICEl 'Original Filed April 29, 1951 Reissues 'June s, 1931 UNITED lsp',r.:ri*;sy

PATENT oFFlcE Original No. 1,941,723, lated January 2, 1,34,

Serial N0. 533,678, April Z9, 1931.

Application for reissue December 28, 1935, Serial No. 58,591

9 Claims.

My invention relates to well drilling tools and relates more particularly to a drilling device for drilling a straight well bore and for straightening a crooked well bore.

In drilling wells by the rotary method the drill bit is often caused to work to the side so that it drills anl inclined or crooked hole. This lateral oil'setting oi the drill is generally caused by its engagement with inclined strata of earth forma- 10 tion.

It is an object of my invention to provide a well drilling device operable partially or entirely to correct the offsetting of the well bore.

It is another object oi the invention to provide 20 outer cutters as they are moved downwardly.

It is another object of the invention to provide a drilling tooladapted to be secured to the lower end of a drilling string of drill pipe and having cuttermeans secured to its lower end and em- 25 bodying a shiftable'pilot member which may be projected from the outer body of .the drilling tool into piloting engagement with the bottom of the well bore. y

It is a further object o! the invention to provide 30 a drilling tool of the character mentioned having an outer body adapted to support outer cutters and an inner body adapted to support inner cutters, there being a keyed engagement between said outer and inner bodies for permitting the 35 inner body to slide downwardly from a position where said cutters are one within the other to a position of projection from the lower end oi the outer body where the inner. cutters act in advance of the outer cutters, said keyed engagement at all 40 times causing the inner body to be positively ro.-

tated by the outer body. A further object of the invention is to provide a drilling tool oi' the character mentioned adapted v to employ replaceable cutters.

Further objects and advantages of the invention will be made evident by the following detailed description of a typical embodiment of the invention. Referring to the drawing, which is 50 Atrative purposes only,

Fig. 1 is a vertically sectioned view showing a preferred embodiment of my invention and illustrating one manner in which it maybe employed in the drilling of a well. A

Pig. 2 is an enlarged fragmentary vertical sectional view showing the lower end of the outer tubular member and showing the inner member in elevation in raised position relative to the outer tubular member. so Fig. 3 is an enlargedv horisontal crosssectional -for maar (Cl. Z55-81) view taken in the plane represented bythe line 3--3 of Fig. 1. I

Fig. 4 is an enlarged fragmentary vertical sectional view taken in the plane represented by the line 4 4 of Fig. 2.

The form Aof my invention shown in the drawing includes an outer tubular body Il having means at -its upper end for connecting with a drilling string I4. In the particular case illustrated a threaded pin l2 is provided on the upper end of the body Il to receive a coupling or collar I2 which is in turn screwed onto the lower end of the tubular stringll. The tubular elongate body Il has a central longitudinal bore I5 extending through it from one end to the other. The bore Il is longitudinally splined through the major portion of its length to provide longitudinal grooves Il. The lower ends of the grooves I8 are closed by a ring or sleeve 20 threaded into a counterbore 2| at the lower end o! the bore l5. The ring or sleeve 20 has a lower end portion 22 projecting below the lower end 22 of the tubular body ll. The invention further provides a tubular body or member 24 telescopically related to the body Il. In the form of the invention disclosed the tubular member 24 is within the bore I5 oi the body Ii and is shiftable longitudinally relative to the body Il. 'I'he inner tubular body or member is provided with longitudinal ribs 25 to cooperate with the longitudinal grooves I8 of the body Il. The ribs 25 are substantially intermediate the ends of the member 2l being located between the upper end portion 26 and the lower end portion 21 ci the inner tubular member 24. Packing means 22 is provided in a counterbore 2| at the upper end of the main bore I5 to seal about the said upper portion 26. The. packing means III includes a lower ring 32 which closes the upper ends of the longitudinal grooves I l, an annular body of packing material 22, an upper ring 24, and a ring nut 25 cooperating with internal threads 38 in the upper portion of the counterbore Il. 'I'he body of packing material 33 is compressed between the rings 22 and 2l by the action of the nut 26 to effectively seal about the portion 26 oi the member 2l. The lower end 21.01' the member 2l may be rounded or convex, as shown in Figs. i and 2.

In accordance with the invention a cutter 40' is provided on the lower end of the inner body or member 2|. The cutter Il may comprise two blades 41 and Il. In the typical structure illustrated a transverse slot 2l is provided in the lower end ofthe member 2l to receive the blades Il and I8. A screw Il is received in a threaded opening l2 in the lower end portion of the member 2l and passes through a hole ll in the central part ot the cutter 4I to 'secure the cutter to the member 2l. A circulation e M extends longitudinally through the member 2l from the 2 i l l 20,405

44 to discharge streams of drilling fluid in front'y 5' of the blades 41 and 48 relative to the direction of rotation of the tool.

. .A cutter 54 is provided on the lower end of the outer body] I to cut the well bore 55 to gauge. The cutter 54 comprises blades 53 projecting downwardly and outwardly from the lower end of the body II. Lugs ilproject outwardly from the lower end portion of the body Il to receive bolts 5I on extensions 52 of the cutter blades 5l. The bolts 5| have suitable nuts and secure the l5 blades A53 to the body II. The blades -53 are carried by or connected by a shoe or ring 55 which is preferably formed or cast integrally with the blades. The ring 55 Visadapted to fit and bear' to receive the downwardly extending enel portion 22 of the threaded ring 20.. The cooperation' of 25 the counterbore 55 with the projecting end portion 22 of the ring 20 may centralize the cutter 54. As shown in Fig. 2, the inner cutter 4U is of such width that the blades 41 and 4l thereof overlap the inner edges 50 of the blades Il of the outer cutter 54. When the inner member 24 is in its highest position relative to the outer meinber Il, as shown in Fig. 2, thelower cutting edges B2 and 6I of the inner and outer cutters and 54 lie in a common plane substantially l5 normal to the longitudinal axis of the members II and 24.

The operation of the device of the invention is as follows: Let it be assumed that the drilling -device is inthe well bore 65, whose lower end 40 portion 56 is offsett Under ordinary Lconditions and when drilling with a typical tool this offsetting Would continue, thereby producing a holeof such crookedness that setting of the casing and other operations would be difficult. With my device, however, it is possible t'o correct the offset condition of the well. To accomplish this the` tubular body II is rst raised by raising the string of drill pipe I4. Upon lifting the body II the inner member 24 projects downwardly from the lower end-:of the outer member II through action of gravity or the fluid pressure acting on the upper end of the member 24 or both. The outer member II may be raised through -a distance greater than the length of the lower p0rtion 21 ofthe member 24 to lift the inner cutter 4|) from the bottom 61 of the well bore, as indicated by dotted lines 55. -'I'his allows the cutter 40 to automatically centralise itself on the axis A-A of the portion of the well bore 55 above the vl0 offset lower end portion 55.` Then, by lowering the drill string I4 and the parts vattached thereto, the cutter 40 may be caused to advance 'veltically downwardly by the action of gravity or uid pressure or both to move from the position in c 05 which it is shown by the broken lines to a of the string VI4 causes the outer body I I and the outer cutter 54l to advance downwardly'. During this downward advance of the outer cutter 54 the inner cutter continues to operate in the counterbore 6! so that' the inner member 24 guides the outer body axially or vertically to continue or extend themain bore vertically as shown by the dotted lines 1I, which extension of the main boreis concentric with the axis AA. When the outer' cutterf 54 reaches and overlaps the inner cutter 40, they progress downwardly together in overlapped relation as shown in Fig. 2.

In the use of my new drilling device the drilling operation may be conducted by steps or stages. For instance, ilfteenfeet of hole may be drilled with the inner and outer cutters 40 and 54 in the overlapped relationship as shown in Figs. l

and 2. The drill string I4 may then be raisedl outer cutter 54 drills downwardly to extend the main bore 55 and the two cutters 40 and 54 may voperate in their nested or overlapping relation to drill another fifteen feet or other selected length of bore. and the above procedure may be repeated. The drilling may be continued by repeating this proc ess of boring a short length of hole and then lforming a pilot bore.

f Although r have 'herein shown and described my invention in simple and practical form, it is recognized that certain parts or elements thereof are representative of other parts, elements. or mechanisms which` may be used in substantially the same mannerto accomplish substantially the same results; therefore, it is to be understood that the invention is not to be limited to the details disclosed herein but is to` be accorded the full scope of the following claims.

Hlaving described my invention, I claim:

1. A drilling device of the character described, including: an outer tubular member having. its upper end adapted to be secured to the lower end of a string ofdrill pipe, and having longitudinal grooves in its internal wall; an inner member slidable within said outer member, said inner member having radially projecting ribsv adapted toengage said longitudinal grooves, the

lower end of said inner member being adapted to receive an inner cutter of a character to make pilot engagement with the bottom of the' hole being drilled; a ring fitted into the lower end of said outer tubular member, said ring pro- A viding a lower end wall for said grooves in said outer tubular member; and means on the lower end of said outer tubular member adapted to receive an outer cutter member.

2. A drilling device of the character described, including: an outer tubular member having its upper end adapted to be secured to the lower end of a. string of drill pipe, and having longitudinal grooves in its internal fwall; an inner member slidable within said outer member, said inner member having radially projecting` ribs adapted to engage said longitudinal grooves, the

lower end of said inner member being adapted to receive an inner cutter of a'character to make pilot. engagement with the bottom of the hole being drilled; a ring fitted into the lower end of said outer tubular member, said ring providing' The device may again be raised outer cutter member; and an outer cutter member secured to said means on the lower end o! said outer tubular member, said outer. cutter member having an opening therethrough for the passage of said inner member.

3. A drilling device of the character described, including: an outer tubular member having its upper end adapted to be secured to the lower end oi' a string of drill pipe, and having internal longitudinal grooves; an inner member slidableI within said outer member, said inner member having radially projecting ribs adaptedr to engage said longitudinal grooves, the lower end of said inner member beingradapted to receive an inner cutter oi a character to make pilot engagement with the bottom oi' the hole being drilled; a ring iltted into the lower end oi' said outer tubular member, said ring providing a lower end wall for said grooves in said outer tubular member; means on the lower end of said outer tubular member adapted to receive an outer cutter member; and an outer cutter member secured to said means on the lower end of said outer tubular member, said outer cutter4 member having an opening therethrough forv the passage of said inner member, the lower cutting edges of said outer cutter member and said inner cutter lying substantially in a radial plane'when said inner cutter is in a fully raised position relative to said outer member.

4. A well drilling tool comprising, a tubular body to be connected with a drilling string, said n body having internal longitudinal grooves, an

elongate member shittable longitudinally in the body, parts in the body at the opposite ends o! the grooves, cutters on the lower ends of the body and member, and ribs on the member cooperable with the grooves for the transmission of rotation and located to engage one of said parts to stop movement oi' the member in one` direction where the cutters are one within the other and to engage the other part to stop movement of the member in rthe other direction where the cutter oi' the member is far in advance o! the cutter of the body.

5. A well drilling tool comprising, a tubular body for connection with a rotary drilling string, a cutter on the lower end of the body acting only on the outer portion of the well bore, a rigid guide member rotatable with the body and freely slidable in the'body between an expanded position where it proiects beyond the lower end of the body and a contracted position substantially entirely within the body, a rotary nsh tail cutter fixed to the lower end oi the member for drilling a pilot bore, means for stopping downward movement ot the member relative to the body when the cutter on the member is in the expanded position where itsupper end is an ap- -preciable distance below the lower end of thev ilrst named cutter, andiluid pressure means for projecting the member from the contracted position where its cutter is within the ilrst named cutter to the expanded position where its cut- 8. A well drilling tool comprising. a tubular body to be connected with a drilling string to be positively rotated and ied thereby, cutting means on the lower end of the body operable to act on the outer portion oi' the well bore,a rigid guide member rotatable with the body and slidable longitudinally in the body between retraited and' .expanded positions. a rotary sh tail pilot cutter iixed on the lower end oi the member operable to only act on the inner portion of the well bore, and hydraulic means for shifting' the member downwardly relative to the body to the expanded position where the pilot cutter is an appreciable distance below thelower end ot said cutting means to'iorm a pilot bore andcooperate with the pilot bore to assist in preventing lateral movement of the guide member whereby the guide member serves to guide the said cutting means.

'7. A drilling device of the character described, including, an outer tubular member tobe secured to the lower end oi a string of drill pipe, and having longitudinal grooves in' its internal wall, an inner member shiftable longitudinally l oi' said outer tubular member providing lowerl end walls ior said grooves in said outer tubular l member, and an outer cutter on the lower end oi' said outer tubular member.

8. A drilling device of the character described including, anv outer tubular member to be se cured to the lower end o! a string of drill pipe. and having longitudinal grooves in its internal wall, an inner member shiitable in said outer member, ribs'on the inner member cooperating with said longitudinal grooves, an inner cutter on the lower end of the inner member operable to make a pilot bore in the bottom of the hole being drilled, a part in the lower end of said outer tubular member providing lower end walls for said grooves in said outer tubular member, means on the lower end of said outer tubular member to receive an outer cutter, and an outer cutter secured to said means on the lower end of vsaid outer tubular member. said outer cutter having an opening therethrough for the passage the inner member cooperating with said longi tudinal grooves, an inner cutter on the lower end oi' said inner member to make a pilot bore in the bottom of the hole being drilled. a part in the outer tubular member providing lower end walls for said grooves, means on the lower end of said outer tubular member to receive an outer cutting means, and an outer cutting means secured to said means on the lower end of said,

outer tubular member, said outer cutting means having\ an opening therethrough for the passage oi! said inner member, the lower cutting edges of said outer cutting means and said inner cutter lying in a common planewhen said inner cutter is in a fully raised position relative to said outer member.

von n. sraoun. 

